2005 BMW 645Ci Sunroof Control Module Replacement Cost

Electronically powered sunroofs use several sensors and a motor to control the operation of a sunroof. The sunroof control module will direct the motor based on the inputs from these sensors, thus preventing damage to the sunroof motor and regulator while allowing for increased and more sophisticated functionality.

When the driver presses the switch to open the sunroof or the wireless control module communicates with the sunroof control module via the body control module, the sunroof control module with read the position of the sunroof and activate the sunroof motor until the sunroof position sensor requests that the sunroof motor stop. Also, when the sunroof is told to open, close or lift completely with a one touch function, the sunroof control module will keep the relay for the sunroof control module active until the sunroof position sensor detects the sunroof has completed movement through the entire range of travel.

Since the sunroof control module controls all aspects of sunroof operation, the sunroof control module can mimic any fault that can be caused by any part of the sunroof control system. This may be failing to open, close or lift, open, close or lift without request, or preventing closing due to a sensed obstruction that is not there.

If the sunroof is in the closed position and is not leaking water into the vehicle during inclement weather, the fuse for the sunroof can be removed to prevent complications from the sunroof control module failing to operate. Also, some vehicles have a manual handle to crank the sunroof open and closed, so this would also prevent complications. In all other circumstances, the sunroof control module should be diagnosed and repaired immediately to protect from theft and water damage.

This is not particularly common, but it does occur. Electronic components fail at random, but some things can lead to early failure. Jump starting a battery backwards or improperly can lead to the early failure of many electronic components, especially control modules. In most cases, the sunroof control module should last the lifetime of the vehicle.

When diagnosing the sunroof control module, the technician will simply compare actual conditions to electronic conditions. In other words, If the technician notes that the sunroof motor is inactive, but the control module shows voltage to the motor, a discrepancy is noted. Discrepancies like this are commonly used as clues which map to the issue. If the technician finds that the issue originates with the control module, whether by physical or scan testing, the module will be verified defective and replaced.

Like any other control module, the location of the sunroof control module will be identified, and the technician will then begin removing all obstructing components needed to access and remove the control module. Once accessed and removed, the connectors are cleaned and inspected, and the new module will be installed. After all components are reassembled on the vehicle, the technician will program the control module, if needed, and test the operation of the system to ensure the customer complaint has been corrected. Sunroof modules will likely need to relearn the path of the sunroof and limits of travel before one-touch operation is possible.

When dealing with electronic systems, especially if the issue pertains to the control module, we recommend thorough diagnostics before replacing parts. In effort to correct an electronic failure, it would be very easy to spend hundreds of dollars replacing components before realizing the issue is more advanced. In the case of electronic failures, diagnostics is a must.

Every possible scenario related to the failure of the sunroof control module can be replicated by one or more failures within the sunroof control system. This means that the control module may be blamed for an external issue, or an external component may be blamed for an internal sunroof control module issue. When the issue has been routed to one circuit, the entire circuit should be tested to prove the diagnosis.

Except for the very advanced DIY mechanic with a strong understanding of computerized circuit diagnostics and testing, this repair should be left to a professional. Again, diagnostics of electronic systems are difficult for the untrained person to perform correctly. Unless safety and diagnostic methods are understood and followed properly, this should be left to a professional.